#!/usr/bin/python3
# SPDX-License-Identifier: AGPL-3.0-or-later
"""
Wrapper to list and handle system services
"""

import argparse
import os

from plinth import action_utils
from plinth import app as app_module
from plinth import cfg, module_loader
from plinth.daemon import Daemon, RelatedDaemon

cfg.read()
module_config_path = os.path.join(cfg.config_dir, 'modules-enabled')


def add_service_action(subparsers, action, help):
    parser = subparsers.add_parser(action, help=help)
    parser.add_argument('service', help='name of the service')


def parse_arguments():
    """Return parsed command line arguments as dictionary."""
    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')

    add_service_action(subparsers, 'start', 'start a service')
    add_service_action(subparsers, 'stop', 'stop a service')
    add_service_action(subparsers, 'enable', 'enable a service')
    add_service_action(subparsers, 'disable', 'disable a service')
    add_service_action(subparsers, 'restart', 'restart a service')
    add_service_action(subparsers, 'try-restart',
                       'restart a service if running')
    add_service_action(subparsers, 'reload', 'reload a service')
    add_service_action(subparsers, 'is-running', 'status of a service')
    add_service_action(subparsers, 'is-enabled', 'status a service')
    add_service_action(subparsers, 'mask', 'unmask a service')
    add_service_action(subparsers, 'unmask', 'unmask a service')

    subparsers.required = True
    return parser.parse_args()


def subcommand_start(arguments):
    action_utils.service_start(arguments.service)


def subcommand_stop(arguments):
    action_utils.service_stop(arguments.service)


def subcommand_enable(arguments):
    action_utils.service_enable(arguments.service)


def subcommand_disable(arguments):
    action_utils.service_disable(arguments.service)


def subcommand_restart(arguments):
    action_utils.service_restart(arguments.service)


def subcommand_try_restart(arguments):
    action_utils.service_try_restart(arguments.service)


def subcommand_reload(arguments):
    action_utils.service_reload(arguments.service)


def subcommand_mask(arguments):
    action_utils.service_mask(arguments.service)


def subcommand_unmask(arguments):
    action_utils.service_unmask(arguments.service)


def subcommand_is_enabled(arguments):
    print(action_utils.service_is_enabled(arguments.service))


def subcommand_is_running(arguments):
    print(action_utils.service_is_running(arguments.service))


def _get_managed_services():
    """Get a set of all services managed by FreedomBox."""
    services = set()
    module_loader.load_modules()
    app_module.apps_init()
    for app in app_module.App.list():
        components = app.get_components_of_type(Daemon)
        for component in components:
            services.add(component.unit)
            if component.alias:
                services.add(component.alias)

        components = app.get_components_of_type(RelatedDaemon)
        for component in components:
            services.add(component.unit)

    return services


def _assert_service_is_managed_by_plinth(service_name):
    managed_services = _get_managed_services()
    if service_name not in managed_services:
        msg = ("The service '%s' is not managed by FreedomBox. Access is only "
               "permitted for services listed in the 'managed_services' "
               "variable of any FreedomBox app.") % service_name
        raise ValueError(msg)


def main():
    """Parse arguments and perform all duties."""
    arguments = parse_arguments()

    subcommand = arguments.subcommand.replace('-', '_')
    subcommand_method = globals()['subcommand_' + subcommand]
    if hasattr(arguments, 'service'):
        _assert_service_is_managed_by_plinth(arguments.service)
    subcommand_method(arguments)


if __name__ == '__main__':
    main()